The cylinder synchronization was so far used in systems with gasoline direct injection. The cylinders are thereby synchronized by an adaption that runs in shift operation based on differences in the segment times regarding its torque input in a fuel neutral manner with respect to the entire motor, whereby particularly a different cylinder filling has no influence on the synchronization. The cylinder synchronization is not active in the lambda-regulated homogeneous operation or homogeneous lean operation at the gasoline direct injection, merely the adaption values from the shift operation are taken over. At an active single cylinder lambda regulation the regulation to a default lambda set value takes place fuel-sided without regard to the torque efficiency. An increased uneven running can result therefore in the homogeneous operation or homogeneous lean operation.
Combustion engines with direct gasoline injection into the combustion chamber and an engine control for illustrating several operating types and several injection sequences per working cycle—for example double injection—get more important. In particular jet-guided combustion processes require a higher metering accuracy of the high pressure injection valves, in order to be able to optimally use all advantages, as for example multi-injections with extremely small single injections. Such a procedure is very advantageous for the starting and warming up of the combustion engine and for the heating of the catalyzer. The necessary metering accuracy is especially in the range of the smallest amounts only able to be illustrated by special procedures.
Combustion engines, which enable a shifted engine operation, often use as so called cylinder synchronization function, which synchronizes the torque parts of the individual cylinders to an entire torque based on the determined uneven running terms. Because the torque is proportional to the injected fuel mass in a shifted operation, the metering tolerances of the injection valves are balanced by this procedure to a high degree.
In the homogeneous operation a single cylinder lambda regulation is preferably used for synchronizing the cylinder individual air/fuel relation. But this procedure is strictly limited. In particular the use of a single cylinder lambda regulation is only possible restrictedly at high cylinder rates and at the use of a turbo charger. Also an asymmetric firing order, for example typical at 8 cylinder engines, provides a big problem for this procedure.
DE 198 28 279 A1 already shows a procedure for synchronizing cylinder individual torque inputs of a multi-cylinder combustion engine, at which an uneven running signal is used for the cylinder synchronization, which is expressed for example in different segment times of the crank- or cam shaft. Based on the uneven running signal the torque inputs of the individual cylinders are synchronized by regulating the injection amount.
The cylinder synchronization function is only active in shift operation. However in homogeneous operation or homogeneous lean operation a factor is used for the injection time correction that has been determined from pre-control engine maps in the shift operation, by the cylinder synchronization is switched to passive.
DE 38 00 176 A1 shows a procedure for a cylinder individual lambda regulation, so that the lambda values for all cylinders that have been measured in the exhaust gas are basically the same. For this purpose a corresponding control time is determined for each injection direction. A similar cylinder individual lambda regulation is also described in DE 199 03 721 C1 as well as in DE 199 09 474 A1.
A tendency for the engine is the use of the gasoline direct injection in combination with turbo charging. Due to elaborate exhaust gas after-treatment the shifted operation is waived and it is only driven in homogeneous operation. The consequence is that none of the actually available procedures can be used for quantity error compensation.